Could it be that there are missing conditions?
Probably ammonia is missing from Na/EtOH
I don't know if there are ammonia-free Birch reductions, but since the OP said that B would be a Birch product, I assume that they want them to apporach it that way.
Anyway, In my opinion B is not the diene that the OP stated, it is an an ionic compound that can be worked up with another equivalent of alcohol or make it react with an electrophile to give the alkylation product.
So what would be D in your opinion, ricecake?
What do you mean by (O)/H2O2? I guess (O) should be O3?